Answers to general HVAC, water heater and plumbing questions
- Should I repair or replace my furnace or air conditioner?
The age of your furnace or air conditioner matters in your decision
If your furnace or air conditioner is 10 years old or older, it may be time to start thinking about upgrading. There have been several technological advances over the past decade that have increased both the energy and operational efficiency of the units. Today's models can help you save on operating expenses, are better for the environment and deliver better overall comfort.
Some recent furnace and air conditioner advancements
Here are just a few of the things that have changed over the years:
- All residential gas furnaces must be condensing as of 2009.
- As of December 19, 2019 the minimum AFUE ratings for residential gas furnaces was raised to 95%
- The requirement of DC variable speed or ECM blower motors in all furnaces as of July 3, 2019
- Minimum SEER ratings for air conditioners of at least 13
- The introduction of variable speed compressors in central air conditioner systems
- How much could I save on my gas bill by upgrading to a high efficiency furnace?
Calculating the savings for furnace upgrades
It’s simple to calculate just how much you could be saving by upgrading your existing furnace to an Energy Star® rated high-efficiency model:
Annual $ savings = (A-B)/A x C
A = Efficiency of the new system
B = Efficiency of the existing system
C = Your current annual heating cost to run your furnace
Example: How much could you save by switching from a 60% efficient conventional gas furnace to an Energy Star® rated high-efficiency gas furnace at 92% efficiency if your annual gas bill for heating is $1,000?
Therefore, A = 92%, B = 60% and C = $1,000
Annual $ savings = (92-60)/92 x 1,000 = $348
This means you could save up to $348 a year in gas costs by upgrading to an Energy Star® high-efficiency gas furnace.
- How much could I save on my hydro bill by upgrading my air conditioner?
Calculating the savings for air conditioner upgrades
It’s simple to calculate just how much you could be saving by upgrading your existing air conditioner to a more energy efficient model:
Annual $ savings = A – B
A = spend per year with your old system
B = spend per year with the new system
A and B are calculated in the same way and as follows:
A or B = (BTU size of the air conditioner)/(SEER rating) ÷ 1,000 x (electricity price per kWh) x (number of hours the air conditioner is used per year)
Note: 1 ton = 12,000 BTU
Example: How much could you save by switching from a 2 ton 10 SEER air conditioner to a 2 ton energy efficient air conditioner at 13 SEER if your electricity cost is $0.10/kWh and the air conditioner gets used 2,160 hours per year (on 24hrs/day for 3 months)?
A = 24,000BTU/10 SEER ÷ 1000 x $0.10/kWh x 2160 hrs = $518.40
B = 24,000BTU/13 SEER ÷ 1000 x $0.10/kWh x 2160 hrs = $398.77
Annual $ savings = $518.40 - $398.77 = $119.63
This means you could save up to $119.63 a year in electricity costs by installing a more energy efficient air conditioner.
- What is an AFUE (Annual Fuel Utilization Efficiency) rating for a furnace?
AFUE and furnace efficiency
The Annual Fuel Utilization Efficiency or AFUE (pronounced ‘A’-‘Foo’) rating for a furnace is the most widely used measure of a furnace’s efficiency. It denotes the actual amount of heat that gets delivered to your home versus the amount of heating fuel that you must supply the furnace.
If you were to look at this in dollars and cents, an example would be for a 95% efficient gas furnace, $0.95 of every dollar you spend on heating gas actually goes into heating your home. Compare this to a 60% efficient furnace where $0.40 of every dollar you spend on fuel is heading straight out of your chimney.
The minimum efficiency standard in Canada for natural gas units being installed in new homes is currently 95%. Most furnaces manufactured before 1990 where 60% efficient. Furnaces manufactured today have AFUE ratings that range from 95% to as high as 98%.
- What is a SEER (Seasonal Energy Efficiency Ratio) rating for an air conditioner?
SEER and air conditioner efficiency
Cooling efficiency for air conditioners is indicated by a SEER (Seasonal Energy Efficiency Ratio) rating, which tells you how efficiently the unit uses electricity. The rule for saving is simple—the higher the SEER rating, the less energy you use and the more you save.
The minimum efficiency standard for units installed in new homes is currently 13 SEER. Most air conditioners manufactured before 1992 had SEER ratings below 7. Air conditioners manufactured today have SEER ratings that range from 13 to as high as 26 in some units.
- What is a DC (Direct Current) variable speed or ECM (Electronically Commutated Motor) blower?
DC (Direct Current) variable speed or ECM (Electronically Commutated Motor) central heating or cooling system blowers
In essence, the DC variable speed or ECM blower in your central heating and/or cooling system is a much more energy efficient way of pushing the air through your home. In single or multi-speed blowers you are left with set speeds at which the blower must run. That means that your system has to pick one of the set speeds to operate on independent of whether or not that much power is actually needed to get the temperature of your home back to your thermostat settings.
In contrast, with DC Variable speed or ECM blowers, any multitude of blower power settings are available which means that your heating and/or cooling system can use less power more often to keep your home’s temperature constant. An added benefit to these types of blowers is that they ramp up to speed which means they are much quieter than their set speed counterparts.
- What is a condensing furnace?
Higher efficiencies through the process of condensing in furnaces
A condensing furnace is the technology that allows modern furnaces to achieve efficiencies above 90%. It works by forcing the hot exhaust gas created by the furnace’s burners through a specialized heat exchanger designed to increase the pressure on that hot gas to the point that it forces a change of state of the gaseous water present in the exhaust into a liquid. When this change of state occurs, a large amount of energy is released in the form of heat. So not only do you get the heat from the burning source fuel, you also get the heat from this chemical change of state. The resulting liquid water that is created is drained out of the furnace. The heat created is transferred over to the cooler air of your home and what you are left with is a combustion waste gas that gets expelled from the system. Because of how efficient this condensing action is, the resulting combustion waste gas is so cool that it can be passed through plastic piping to the outside; this means you don’t need a traditional chimney.
- What is EER (Energy Efficiency Ratio)?
EER (Energy Efficiency Ratio) another measure of your air conditioner’s energy efficiency
Sometimes cooling devices such as central air conditioning systems are rated using EER (Energy Efficiency Ratio) versus SEER (Seasonal Energy Efficiency Ratio). EER is a measure of how efficiently an air conditioner will operate when the temperature outside is at a specific level – the higher the EER, the higher the efficiency of the unit. The main difference between the two measurements is that EER measures efficiency at peak day operations while SEER measures efficiency over the entire cooling season.
- What is a BTU (British Thermal Unit)?
The BTU measure of power for furnaces and air conditioners
The British Thermal Unit, or BTU for short, is a traditional measure of energy. In North America, it is commonly used to describe the power of heating and cooling systems. When used to describe power, BTU per hour (BTU/hr) is actual the technically correct unit, but it usually gets abbreviated to simply BTU.
The BTU also tends to be more commonly used with furnaces rather than air conditioners, which tend to get described in tons instead. Nevertheless, it is an easy conversion since 1 ton is equal to approximately 12,000 BTU. The higher the BTU rating of your system, the larger its heating or cooling capacity (meaning it can handle bigger areas) and the more energy it uses. This is why proper furnace and air conditioner sizing is so important.
- What is a ton?
The ton measure of cooling capacity for air conditioners
In North America, air conditioner equipment power is often described in tons of refrigerant. A ton of refrigerant is defined as the cooling power of one ton of ice melting in a 24 hour period. 1 ton is also equal to approximately 12,000 BTU. In the HVAC industry we throw around the term ton to describe the size of the air conditioner you need. In other words, the greater the number of tons of the unit, the larger the capacity of the unit which means the bigger the area it can cool. The larger the ton rating, however, the more energy the unit will use. This is why proper furnace and air conditioner sizing is so important.
- What is a refrigerant?
The stuff that enables my air conditioner to cool my house
A refrigerant is a compound that is used in air conditioning systems to absorb and release heat. It does this by changing states from a gas to a liquid using a compressor. In a central cooling system, the compressor, which is usually located outside, compresses the refrigerant gas into a liquid and pumps it into a coil usually located inside your home on top of your furnace or air handler. The warm air from your house then passes over this coil containing the compressed liquid gas which absorbs the heat from this warmer air and changes state back to a gas (in essence a boiling process). This gas is then pumped back outside to the compressor which turns it back into a liquid thus releasing all of the heat energy it had absorbed to the outside environment.
- What does HVAC stand for?
Heating, Ventilating and Air Conditioning – HVAC
HVAC is an acronym that stands for Heating, Ventilating and Air Conditioning. The heating and cooling industry often labels itself with this acronym. In fact, furnace and air conditioner sales, installation and repair companies will also classify themselves as HVAC contractors.
- How do I size my new furnace or air conditioner?
The proper sizing of your furnace or air conditioner will determine how much usable efficiency you get out of them
Having a furnace or air conditioner of correct size will result in much more efficient operation during the seasons in which they are used. Oversized units will only run for short periods of time which means they will never run in their peak efficiency modes. Rather, they will always be used in the less efficient start up phase of operation. Conversely, undersized units will stay running much too long, and as a result not only be inefficient, but may also be more prone to breakage due to over exertion.
So, how do you size your equipment? The best and easiest way to do this is by having a contractor use a home heat loss calculation that is available from the Canadian Standards Ass